Split turbo pipe gives you your noise, and is in the right time window, and fairly simple to replace- can be various parts but pattern replacements are cheap (well, cheap in money, expensive in lost skin). Wouldn’t neccesarily smoke though.
Smoky I’d suspect EGR on general principles. Not sure what the options are for blanking with an 07, you might have more issues with emissions control than mine. Otherwise take it off, clean it out- even if it’s not gone wrong yet, it will.
I’m assuming from the name you’re in wales but if you’re Edinburgh-ish I think my faultreader would work on yours if you want to check it out?